标题： 早期类型星系棒的傅里叶分解 显示英文标题

标题： Fourier Dissection of Early-Type Galaxy Bars

摘要： 本文报告了一项针对早型星系的近红外调查，旨在提供关于条状结构强度、核球、盘状结构以及条状结构参数的信息，在一个统计上定义明确的S0-Sa星系样本中。 早型星系的优势在于它们的条状结构相对不受尘埃、恒星形成和螺旋结构的影响，这些因素在晚型星系的条状结构研究中会带来复杂性。 我们描述了该调查，并展示了对26个早型星系中条状结构的相对傅里叶强度振幅的详细分析结果。 我们还评估了这些振幅随半径变化的对称性假设，该假设最近被用于晚型星系的条状结构与螺旋结构的分离。 结果表明，条状结构的径向傅里叶轮廓存在广泛的多样性，从可以用单个高斯成分表示的简单对称轮廓，到可以用两个重叠的高斯成分表示的对称和非对称轮廓。 还发现了比这些更复杂的轮廓，通常由于多个类似条状结构的特征，包括扩展的椭圆或透镜状结构。 基于引力条状结构扭矩指标Q_b，双高斯条状结构平均比单高斯条状结构更强，至少在我们的小样本中是如此。 我们表明，已发表的数值模拟中，条状结构将大量角动量传递给晕的情况可以解释许多观测到的轮廓。 模型中遇到的可能性在观测系统中似乎得到了很好的体现。 显示英文摘要

摘要： This paper reports on a near-infrared survey of early-type galaxies designed to provide information on bar strengths, bulges, disks, and bar parameters in a statistically well-defined sample of S0-Sa galaxies. Early-type galaxies have the advantage that their bars are relatively free of the effects of dust, star formation, and spiral structure that complicate bar studies in later type galaxies. We describe the survey and present results on detailed analysis of the relative Fourier intensity amplitudes of bars in 26 early-type galaxies. We also evaluate the symmetry assumption of these amplitudes with radius, used recently for bar-spiral separation in later-type galaxies. The results show a wide variety of radial Fourier profiles of bars, ranging from simple symmetric profiles that can be represented in terms of a single gaussian component, to both symmetric and asymmetric profiles that can be represented by two overlapping gaussian components. More complicated profiles than these are also found, often due to multiple bar-like features including extended ovals or lenses. Based on the gravitational bar torque indicator Q_b, double-gaussian bars are stronger on average than single-gaussian bars, at least for our small sample. We show that published numerical simulations where the bar transfers a large amount of angular momentum to the halo can account for many of the observed profiles. The range of possibilities encountered in models seems well-represented in the observed systems.